Minimal invasive surgeries which utilize stents have a certain advantages such as small wound size, reduced complications, and satisfying prognosis, in comparison with traditional peripheral artery surgeries. Currently, minimal invasive surgeries become major methods for treating peripheral artery stenosis.
As shown in FIG. 1, a delivery system is needed to implant intravascular stents into a body. A delivery system being currently used is shown in Chinese Patent Application CN201110190183.4, which includes a hollow inner tube and an outer tube connected to each other. Guide wires used during surgery pass through the hollow portion in the inner tube and intravascular stents are disposed between the inner tube and the outer tube. When a surgery is being performed, a tube assembly of the delivery system can be introduced to the target treatment area by the guide wires, and then the outer tube is withdrawn by a control assembly, whereby the intravascular stents are unfolded and positioned on the intravascular walls. However most of the self-expandable stents cannot be accurately located by using such delivery systems due to high retractability and highly axial retractability of the stents. Therefore, such a delivery system doesn't meet the requirements for surgery. Chinese Patent No. 201310315654.9 owned by the present applicant reveals a delivery system for intravascular stents. However, it is difficult to manufacture a rotation driving assembly in such delivery system, and if such delivery system is used to position a stent with long axial length, it needs a hand shank with increased length. It is inconvenient for the doctors to operate such delivery system.